Boat hull strake design

ABSTRACT

A system for increasing the buoyancy of a boat operating in the water and to reduce the wetted-surface-friction of the water against the hull of the boat. The system includes a multiple of strakes attached to the bottom side of the boat. The strakes are instrumental in creating a multitude of bubbles on which the hull of the boat will ride which increases the efficiency of the power of the motor or motors powering the boat. The strakes are arranged in series along the hull of the boat and can increase in size from the bow of the boat to the stern. The strakes are also increasing in depth from the bow of the boat to the stern. The strakes may be attached to the boat as a retro-fit or may be added when manufacturing the boat.

BACKGROUND OF THE INVENTION

Designers and manufactures of planning boat hulls have for years used avariety of means to attempt to have the least amount of solid water incontact with the hull of a boat when planning on the hull surface.Probably the earliest designs for hulls on boats without the usualframing, utilizing overlapping planking, which is known as “Lapstrake”or “Clinker” style hulls, which were originally created by the Vikings.This construction method of the overlapping planking was applied by someearly wooden boat builders to eliminate conventional framing and alsoreduce the weight for planning hulls, which incidentally created somebubbles for probably the very first time, which reduced some of theordinary water-to hull friction from solid water under the hull. Othershave tried cross-wise steps in their hulls to draw air under the hulland create bubbles to reduce friction. Still others have triedlength-wise air tunnels and some bubble creation, again to reducefriction. Some have tried sponson-like configurations with the sameobjective to reduce friction between the boat hull and the solid water.The commonly used strakes in today's boat hulls were originally createdto assist the then new Deep-V hull designs that could not otherwise havea satisfactory planning surface. Those now in use in a variety ofplanning hulls are designed to force water out and away from the hullfor increased hull lift out of the water for friction reduction. Some ofthem extend too close to the bow of small boats and in rough water cancatch a wave and cause a nasty, sudden and dangerous abrupt turning ofthe boat.

BRIEF DESCRIPTION OF THE INVENTION

The inventive use of attachable strakes, or designed into the hull,forces the normally outward flowing water back under the hull and thisforced redirection of the water back under the hull, a massive bed offoam bubbles is created resulting in reducing the original planningsurface friction to a minimum. This inventive concept uses strakes whichare designed to put the largest possible amount of air containingbubbles under the largest amount of the otherwise planning surfaces. Byusing multiple, uniquely surfaced, inwardly canted and tapered strakeswith added ridges and steps, a huge amount of bubbles is created andthey are kept under the hull as long as possible. The strakes are alsodirected to those areas under the hull where they are most desired. Thisenables the hull to ride with very low friction thereby reducing fuelconsumption and the related pollution of the environment for maximumefficiency and conservation in today's world.

These planning area strake features can be used in a variety of shapesand configurations. Other air introduction or bubble creating designsrequire restricted hull designs to enable their use. This is the firstinventive concept that will get boat hulls onto a plane mode sooner,with less power required to do so and have the least amount of surfacefriction regardless of the planning speed at which the boat isoperating. For the first time theses bubble creating strakes can be usedon any manufacture's hull for complete freedom of hull design comparedto all present designs. They can also be manufactured separately to beadded to hulls already in service, as a retro-fit, with huge gains fortheir owner, for increased speed and performance, economy and reductionin pollution. It is also a well known fact that salt water, whenchurned, easily creates bubbles which can be seen by watching a boat,when traveling in salt water, the propeller churns up the salt in thewater and the boat leaves a long trail of bubbles in its wake. Theinventive concept takes advantage of this phenomenon. There are alsoknown semi-displacement hulls which can get up to plane infrequently.Now that higher powered engines are available, and newer hull forms withlarge planning areas are being used, these boats also need the advantageof the bubble-ride concept.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a prior art bottom of a boat;

FIG. 1B is a prior art back view of a boat;

FIG. 1C is side view of a prior art boat;

FIG. 1 illustrates a side view of a boat with strakes attached;

FIG. 2 shows the action of the strakes;

FIG. 3 is a perspective view of the strakes themselves;

FIG. 4 is a bottom view of the strakes while increasing in size;

FIG. 5 is a bottom view of a boat with a multiple of strakes;

FIG. 6 is a rear view of a boat with a strake line attached to theBottom;

FIG. 7 is a magnified view of a single back end of a strake.

FIG. 8 illustrates the creation and the concentration of the bubbles;

FIG. 9 is the rear view of the hull of FIG. 8.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1A-1C illustrate a conventional design of a boat showing Thebottom of a boat, a rear view and a side view.

FIG. 1 illustrates a side view of a boat having several strakes attachedto the bottom from the keel shown at 2, the side of the boat hull 3 andfurther up the side shown at 4. These strake series are space apart fromeach in a horizontal manner and they can be of different lengths.

FIG. 2 shows how the individual strakes 5 create a a stream of bubbles5. The individual strakes are slanted upwardly as seen from thedirection of the travel of the boat. This slant is especiallyconstructed because , once the water flow passes over the strakes, itcreates somewhat of a venturi effect which aids in the creation of thebubbles which is the basic aim of the inventive concept.

FIG. 3 is a perspective view of a line of strakes where the slant of theindividual strakes can be observed. The individual strakes are alsocanted relative to the hull of the boat or expressed differently, thetrailing edge of the strakes are angled toward the keel and the stepsare progressively thicker toward the stem and they are higher on thechine-side than the keel side.

FIG. 4 shows a line or series of strakes where an increase in size alongthe line can be observed. The increase in size as shown at 5, 6 7 and 8starts in the vicinity of the bow of the boat hull and keeps increasingtoward the rear of the hull. It also can be seen that the strakes aregetting wider toward the stem so that water confined between the seriesof strakes has less and less space to move toward the stem and, hence,the spillover that is caused, creates more bubbles than would strakeswith parallel sides. The strakes of themselves are adding more bubblesunder the hull. The strakes are progressively deeper from the bow towardthe stern because the bed of bubbles is being continually added to asthe as the hull goes through the water and the increased holding andadded confining ability of the deeper and deeper strakes is essentialfor maintaining the largest possible bed of bubbles. By choosing anincrease in size, the effect of the increase in bubble intensity ismultiplied which aids in reducing the friction of the hull surfaceagainst the stream of water.

FIG. 5 illustrates the bottom of a boat hull and the strakes as attachedto the hull are shown at 2 at the lower most edge of the hull andincreasing the distance from the lower most edge at 3 and then 4. Thisview also shows the different sizes of the individual strakes in aseries as the sizes increase from the bow of the hull to the rear. ThisFIG. 5 also shows that the size of each longitudinal row increases fromthe chine of the hull and down to the keel of the hull.

FIG. 6 illustrates the rear of the boat hull. Again the line of thestrakes can seen from the bottom at 2 and up the sides at 3 and 4. Thecircle 9 shows an individual strake which is more clearly shown in FIG.7. In this view it can be seen that the strakes 10 are canted relativeto the bottom of the hull. That is, the bottom of the strake 10 and allof the strakes is retained in an angled position relative to ahorizontal plane. This then can be termed that the strakes are canted.

FIG. 8 shows the creation of the bubbles by the various

1. A system to increase the buoyancy of a boat, said system includes aseries of longitudinal strakes attached to a hull of said boat, saidstrakes being slanted and canted relative to said hull of said boat tothereby create bubbles as said boat moves through the water, saidbubbles create said buoyancy and reduce friction of the water againstsaid hull of said boat.
 2. The system of claim 1, wherein there is amultiple of said series,
 3. The system of claim 1, wherein there are atleast three series of said stakes on each side of said hull.
 4. Thesystem of claim 1, wherein said stakes in said series increase in widthfrom a bow to a stern of said hull.
 5. The system of claim 1, whereinsaid stakes in said series increase in depth from a bow to a stern ofsaid hull.
 6. The system of claim 3, wherein said series of said strakesdiminish in size from the keel of said hull and up the chimes of saidhull.
 7. The system of claim 1, wherein a series of steps areincorporated into said strakes.